In a service delivery environment through public networks centered around the Internet, values of all information are generally concentrated on a server side rather than a client side.
In other words, each client (terminal device) is basically a mere viewer browsing information on the Internet. Each client issues requests for various information to the Internet, which in return may obtain such information for the client. It means that all information is collected on the Internet and it only offers formulaic information unidirectionally. For this reason, it is difficult for manufacturers of client terminal devices to create an added value.
In order to change such a circumstance, the server-client relationship must be reversed by inverting the access direction. That is, when there is a home network connected to the Internet, it is necessary to create an environment for allowing the Internet to access the home network to receive a service therefrom.
To achieve this, each apparatus connected to the home network must be uniquely identifiable from the Internet, and intra-home routing and security problems must be solved. One of the technologies to address this issue is the IPv6 (Internet Protocol version 6).
However, considering the environment surrounding the current carriers and Internet service providers in Japan, it may be considerably long before IPv6 becomes widespread. For example, the currently used IPv4 machines need at least 2 to 3 years for their depreciation and IPv6 service is offered on a test basis only.
In order to immediately achieve an IPv6-enabled network, manufacturers must expand their business to ISP level services, which is very costly and unrealistic for most of them. Since existing home networks vary broadly in their structures and also in connection mechanisms depending on the carrier and ISP, there is a need for a mechanism for absorbing all these differences to achieve the IPv6 environment with a standardized approach.
The Japanese Unexamined Patent Application Publication No. 2001-274845 (JP-A-2001-274845) discloses pertinent prior art, although it does not contradict with novelty and inventive step of the present invention.
In the conventional IPv4 environment, the following problems arise in an attempt to achieve such bidirectional accesses as would be possible in IPv6 networks between the home network and the Internet.
For example, when installing a network home appliance at home in the current IPv4 environment, the appliance should be connected to a router connected to the Internet through the home network. Accordingly, an IP address of the network home appliance becomes a private address and cannot be accessed from non-home network.
Thus an access to the network home appliance has been conventionally achieved by employing a dedicated router capable of controlling the network home appliance, or by first accumulating information for controlling the home network appliance at a data center provided on the Internet and then retrieving the information by performing polling from the network home appliance.
However, such a dedicated router decreases the system's versatility and increases the cost. When retrieving the control information by polling, real time accesses cannot be made and the network and server load increases.
In order to overcome these challenges, a network connection method and a relay device were disclosed by the present assignee in International Application PCT/JP 2005/9280, filed on May 20, 2005, the disclosure of which is incorporated herein by reference. This invention enables bidirectional communications between the home network and the Internet by relatively simple means by establishing a tunneling connection session between a computer system in a private network and an InterServer on the Internet.
However, the relay device disclosed in the above application mainly operates as a router or is installed in the form of a virtual device driver and a program in each client apparatus and therefore further improvement may be possible. That is, there can be provided means for operating as a non-router and establishing a connection similar to one in the above disclosure even on networks connected with apparatuses such as printers, cameras, and scanners in which said means cannot be installed as a virtual device driver and the like.
Considering the above situation, the purpose of the present invention is to provide an Internet connection system for enabling virtual network communications via the home network and the Internet by relatively simple means without having to switch routers in a private network environment connected to apparatuses with no virtual device driver installable.